Serial Port Communications
4
0
1
-
9
2
-
4
A
.
v
e
r
9
7
0
2
0
-
0
0
0
9
4
–
13
Reading/Writing in Gould Modbus Mode
Gould Modbus supports three types of variable data, short integer, long integer
and floating point, but all registers are addressed as word (two byte) registers.
A “short integer” value is contained in one register whereas a “long integer” or
“floating point” value requires two contiguous registers. The registers are
defined as Read or Read/Write.
An appropriate password must be downloaded to the password register prior
to writing to most registers. The User Level 1 (L1) user password
3142
will
allow access to those registers which have been pre-defined as user
configurable. Other writable registers can only be downloaded or changed by
SpectraSensors support personnel using a User Level 2 (L2) password.
To enable Modbus communications:
1.
Confirm that the serial cable has been properly connected. See
“Connecting the Output Signals”
on page 2-5.
2.
Power up the analyzer (see
“Powering Up the Analyzer”
on page
3-1).
3.
Press the
#
key followed by the
2
key (Channel A) or the
#
key
followed by the
3
key (Channel B). The LCD prompts for a numeric
password. Enter the user password (
3142
) on the keypad, then
press the
*
key to enter the number to enter
Mode 2
(Set Parameter
Mode - Channel A) or
Mode 3
(Set Parameter Mode - Channel B).
Use caution when writing to registers as changing the value of a
writable register may affect the calibration of the analyzer.
<SET PARAMETER MODE>
Enter password
v2.41 08-12-08 DM
<SET PARAMETER MODE>
S Factor
1.00000
Enter a value
UK Distibution by IMA Ltd
Tel: +44 (0)1943 878877 Email: [email protected] Web: www.ima.co.uk